The Joint United Nations Program on HIV/AIDS (UNAIDS) has adopted the Sustainable Development Goals (SDGs) to end the HIV/AIDS epidemic by 2030. Several factors related to the non-suppression of HIV, including interruptions of antiretroviral therapy (ART) and opportunistic infections could affect and delay this projected epidemic goal. Human T-Cell leukemia virus type 1 (HTLV-1) appears to be consistently associated with a high risk of opportunistic infections, an early onset of HTLV-1 and its associated pathologies, as well as a fast progression to the AIDS phase in co-infected individuals, when compared to HIV-1 or HTLV-1 mono-infected individuals. In Gabon, the prevalence of these two retroviruses is very high and little is known about HTLV-1 and the associated pathologies, leaving most of them underdiagnosed. Hence, HTLV-1/HIV-1 co-infections could simultaneously imply a non-diagnosis of HIV-1 positive individuals having developed pathologies associated with HTLV-1, but also a high mortality rate among the co-infected individuals. All of these constitute potential obstacles to pursue targeted objectives. A systematic review was conducted to assess the negative impacts of HTLV-1/HIV-1 co-infections and related factors on the elimination of HIV/AIDS by 2030 in Gabon.

Central Africa is the largest region of human T-cell Leukemia virus (HTLV-1) endemicity with several million people estimated to be infected. Based on the study of the LTR region, it is also the region with the highest HTLV-1 diversity, with presence of genotypes a-b, d-g. However, complete genomic sequences are still lacking for Central African genotypes. Here, we report the first large collection of complete HTLV-1 sequences for genotypes b, d and f from Central Africa and neighboring countries. We identified substantial diversity within the HTLV-1b genotype, including a newly defined clade that we designated HTLV-1b-del. It mainly comprises strains from the Democratic Republic of the Congo (COD) and neighboring countries and is characterized by a distinctive 12-bp-long deletion. We also generated the complete sequence of STLV-1 strain from Allenopithecus nigroviridis from the COD. This strain belongs to the PTLV-1b genotype and carries a 12-bp duplication in the pX region. Lastly, we found that, except for HTLV-1a strains, HTLV-1 genomes generally lack open reading frames encoding the canonical accessory protein P12; instead, they encode either shorter versions of the protein or an ORF lacking a start ATG codon. This work substantially expands the genomic landscape of HTLV-1 in Central Africa and provides a critical resource for understanding viral diversity.

Significant advancements in, and increased access to, antiretroviral therapy (ART) have substantially reduced the risk of mother-to-child transmission (MTCT) of HIV. However, antiretroviral drug resistance (HIVDR) is a serious challenge affecting both adults and children. Because of high HIV prevalence and genetic diversity, Central Africa is considered the epicenter of the epidemic. Yet information on drug resistance profiles and clinical efficacy of newer antiretroviral agents among children is limited compared to adult cohorts. Not to mention that several countries of the subregion, including Gabon, Chad, and São Tomé and Príncipe, lack updated epidemiological data. This article aims to provide an overview of HIV prevention of mother-to-child transmission (PMTCT), focusing on four key elements: prevalence rates; associated risk factors; molecular characterization of pediatric HIV; and virological response to antiretroviral therapy in Central Africa. We have gathered studies published between 2014 and 2026 across PubMed and Research Gate databases and AJOL. The synthesized data reveal high genetic variability of HIV and a dominant CRF02AG variant within the considered populations. The results of this study indicate a range of virological failure rates in the pediatric population on ART for at least six months, ranging from 11.1% to 89.1%. These rates are attributed to a high frequency of resistance-associated mutations (RAMs) and suboptimal adherence to antiretroviral treatment. The main determinants of non-adherence are social stigma, geographic barriers (distance from specialized care centers) and orphan status. Strengthened virological and molecular surveillance programs must be implemented in Central Africa to ensure optimal care for pregnant women, children, and adolescents. Addressing these gaps is imperative in order to bridge the gap between the current epidemiological profile and the WHO’s goals for the elimination of pediatric HIV.

The adoption and widespread use of dolutegravir (DTG)-based antiretroviral therapy (ART) are key strategies for achieving global 2030 targets, though emerging resistance threatens long-term success. This study evaluated HIV-1 drug resistance mutations among participants experiencing virological failure in Bunia, Democratic Republic of the Congo (DRC). Over an 11-month period, a prospective cohort study was conducted across 20 healthcare facilities in Bunia, Ituri Province. Targeted genotyping of the HIV-1 pol gene was performed, antiretroviral resistance mutations were identified, and genotypic sensitivity scores (GSSs) were calculated using the Stanford HIV Drug Resistance Database. Virological failure occurred in 12.3% (74/603) of participants, and targeted genotyping of the HIV-1 pol gene was attempted on 53 samples. This subgroup comprised 41 females (55.4%) and 33 males (44.6%), with a median age of 36 years (IQR: 17.0) and a median ART duration of 24 months. Subsubtype A1 predominated (38%), followed by subtypes G (26%) and D (9%); recombinant forms, led by CRF02_AG, accounted for 16%. Mutations associated with resistance to reverse transcriptase inhibitors were detected in 26.4% (14/53) of successfully sequenced samples, compared with 33.9% (18/53) for integrase strand-transfer inhibitors. Overall, GSS analysis revealed that 98% (50/51) of evaluable participants scored 3, whereas only 2% (1/51) scored below 3. This study demonstrates that DTG-based ART remains highly effective in Bunia. To optimize treatment outcomes and support progress toward the UNAIDS 95-95-95 targets, targeted interventions to enhance treatment adherence are urgently warranted.

Background/Objectives: Human T-cell lymphotropic virus type 1 (HTLV-1) is an oncogenic retrovirus that infects an estimated 5–10 million people worldwide. In Gabon, despite a high seroprevalence (7.3–8.7%), documented cases of associated pathologies remain rare, suggesting significant underdiagnosis driven by a lack of clinical awareness. This study evaluated the knowledge, attitudes, and practices (KAP) concerning HTLV-1 among Gabonese healthcare professionals. Methods: A descriptive cross-sectional study was conducted among 392 healthcare professionals across four provinces in Gabon using a standardized questionnaire. Bivariate comparisons were performed using chi-square (χ²) and Mann–Whitney U tests, followed by multivariable binary logistic regression to identify independent predictors of HTLV-1 awareness. Results: Overall, 79.9% of the participants had never heard of HTLV-1. Awareness of the virus was critically low among nursing and obstetric staff (7.2%), whereas physicians demonstrated the highest level of knowledge (57.1%). In the multivariable analysis, independent predictors of higher HTLV-1 awareness included being male (aOR = 2.93; 95% CI: 1.60–5.39; p < 0.001), holding a university degree (aOR = 3.43; 95% CI: 1.66–6.89; p < 0.001), and working as a physician (aOR = 2.75; 95% CI: 1.24–6.10; p = 0.013). Conclusions: A critical HTLV-1 knowledge deficit exists among healthcare professionals in Gabon, particularly among frontline nursing staff, which likely explains the low reporting of associated diseases. Integrating HTLV-1 into medical and paramedical curricula, launching targeted educational campaigns, and implementing national screening protocols are urgently required to improve diagnosis and prevent transmission.

Sub-Saharan Africa is an endemic region for human T-lymphotropic virus type 1 (HTLV-1). While high prevalence rates have been reported across Gabon, systematic screening of blood donors has not yet been implemented at the national level. A cross-sectional study was conducted on 2,375 blood donations from 2,303 blood donors at the Amissa Bongo Teaching Hospital Center in Franceville. Serological screening was performed via ELISA, followed by Western Blot confirmation and PCR-based proviral DNA amplification of the env gene. The overall HTLV-1 seroprevalence was 2.1% (95% CI: 1.6%–2.7%) at the donation level and 1.8% (95% CI: 1.3%–2.5%) at the donor level. The seroprevalence in Franceville was significantly higher than at the national blood bank in Libreville (ORa = 2.52; 95% CI: 1.5–4.2). History of blood transfusion was the only risk factor significantly associated with HTLV-1 infection (OR = 3.73; 95% CI: 1.3–9). Molecular analysis revealed a predominance of the HTLV-1b subtype (32/33), alongside one HTLV-1d strain, a subtype primarily reported in non-human primates. The high HTLV-1 seroprevalence among blood donors in southeastern Gabon, combined with the identification of a history of transfusion as a significant risk factor, represents a major challenge for transfusion safety in a semi-rural area. These results underscore the urgent need to integrate systematic HTLV-1 screening into the transfusion safety algorithm in Gabon to interrupt the cycle of iatrogenic transmission. IMPORTANCE: Human T-lymphotropic virus type 1 (HTLV-1) remains a major public health problem in Central Africa, with Gabon being a major endemic hotspot. This study addresses a critical issue for blood safety in semi-rural areas, where prevalence in the general adult rural population is exceptionally high, ranging from 7.3% to 8.7% according to previous studies. Here, we report a prevalence of 1.8% among blood donors in southeastern Gabon, a rate 2.5 times higher than that of blood donors in the capital. Moreover, a history of transfusion was identified as the only significant risk factor associated with HTLV-1 infection, directly demonstrating active iatrogenic transmission in the absence of systematic screening. Furthermore, the discovery of the rare HTLV-1d subtype highlights the persistent potential risk of zoonotic and human-to-human transmission in these forest-adjacent ecosystems. These results provide compelling evidence for the urgent integration of HTLV-1 screening in endemic rural areas of Gabon.